Vibration Isolation

A vibration isolation system is used to isolate the sources of vibration from the system of interest, as shown in the model below, where the base is moving for various reasons, such as a close machine tool is operating, or a heavy truck is passing by. We are interested in keeping the device M (which may be a machine tool) from vibration displacement transmitted from the base. To achieve this, an isolator is placed between the base and the device. Isolators are usually made of highly damped materials such as rubber, which, when placed between the base and the device, changes the stiffness and damping between the source of vibration and the device that is to be protected from vibration.

Another way to isolate vibration is to keep the vibration source from transmitting to the base. This is done by placing an isolator between the vibration source and the base. The model for this kind of vibration isolation is shown as below. We are most interested in isolating the force from transmitting to the base. Force transmissibility is a measure to characterize how good the isolator works.